Albert schmitz



UNITED STATES PATENT OFFICEQ ALBERT SOHMITZ, OF ESSEN, GERMANY, ASSIGNORTO THE FIRM OF FRIED. KRUPP, OF SAME PLACE.

plate not exposed to the projectile.

PROCESS OF IMPROVING THE QUALITY OF STEEL ARMOR-PLATES.

SPECIFICATION forming part of Letters Patent No. 506,446, dated October10, 1893 Application filedMay 6, 1893. Serial No. 473,266. (Nospecimens.)

To all whom it may concern:

Be it known that I, ALBERT ScHMrrz, a subj ect of the King of Prussia,residing at Essen, in the Kingdom of Prussia, Germany, have invented anew and useful Process for Improving the Quality of Steel Armor-Plates,of which the following is a specification.

This invention refers to a process forimproving the quality of steelarmor plates consistin g in the combination of the three followingoperations in the order indicated: first, hardening the plates byimmersing the whole plates in oil, water, or other media, after haw ingpreviously raised them to a temperature at which the molecules haveacquired the ca pability of ready re-arrangement; secondly, annealingthe plates at a temperature which is as high as possible without howeverreaching the temperature at which said capability of ready rearrangement begins; thirdly, hardening the plates on one side or face atthe same or at a lower temperature than that specified in the precedingor second operation.

In order to avoid great deviations fromthe form desired to be given tothe plates through invention consists in interposingbetween the secondoperation of annealing and the last operation afurther new operation,namely the hardening of the dead or false sidevof the hardening theannealing heat'may be used. By this interposed operation, the hardeningefiect of which is nullified or destroyed by the heating of the lastoperation, the plate the finished hardened plate corresponds with theform before the commencement of the operations. For the same purposethe, process For this maybe carried outalso ina simplified manner,consisting in substituting thev first operation of chilling the wholemass of the plates, by chilling only the side or face of the plate,which is not to be exposed to-projectiles, then glowing the whole massof the plate and finally hardening by chilling the side or face of theplate whichis to be exposed to projectiles. -By the subsequent'hardeningof both sides of the plate and by the intervening reheating between thetwo hardening operations exactly the sa'me properties are given in thecase of thinner plates, to the main mass of the latter, while thecentral layer of the metal of very thick platesdoes not receive theseexcellentproperties in a quite perfect degree.

.one sid'e, consisting in first hardening the plates throughout theirentire mass by chilling,then annealing in their entire mass, thenhardening the side not to-be exposed to the action of projecti1es,andfinally after reheat ing again hardening by'chilliug the side or face tobe exposed to P jectiles, substantially as set forth. I

-2. Aprocess for hardening armorplates on one side, consisting in firsthardening the; plates by chilling on the side not to be exposed to theaction of projectiles, then annealing the plates in their entire mass,"and finally again hardening the plates on the side to be exposedtoprojectiles by chilling,,substantially as set forth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

ALBERT SCHMlTZ.

Witnesses:

j MAX UHLENHAUT,

ALBERT KLINGHAMMER.

